The purpose of this study is to use near infrared light to noninvasively image cerebral oxygen saturation and blood flow in relation to the development and progression of infant brain injury. Current imaging techniques used in the newborn ICU, such as ultrasound and CT, are only able to visualize cerebral structure and provide no information about cerebral function. Near infrared optical tomography using time-of-flight and absorbance (TOFA) provides real-time visualization of cerebral function as well as structure. It is noninvasive and therefore can be used for prolonged periods of time. Since early brain injury involves changes in cerebral function without alterations in cerebral structure, TOFA may allow recognition of brain injury prior to the development of irreversible structural changes.